HIV-associated nephropathy (HIVAN) is the most common cause of chronic renal failure in HIV-1 infected patients. The most prominent histologic feature of HIVAN is dilatation of the renal tubules. Investigators in our laboratory have previously demonstrated, in biopsy specimens from patients with HIVAN, that renal tubular epithelial cells are infected with HIV-1. However, the cellular events following HIV-1 infection, contributing to progressive renal failure in HIVAN are not well understood. We have demonstrated previously, that HIV-1 infection may involve epithelial cells from several portions of the nephron, including the proximal tubule. We have isolated proximal tubular epithelial cells from HIVAN biopsy specimens and conditionally immortalized them with the temperature-sensitive SV40 large T antigen. These cells (HPT-1) grow indefinitely under permissive conditions (33C), and when differentiated at 37C, express typical proximal tubular phenotypic markers. The purpose of the proposed-studies is to determine the host genes that are differentially expressed following infection of renal tubular epithelial cells with HIV-1. Once candidate host genes are identified, we will map the HIV-1 responsible for inducing altered expression of these genes. In the proposed studies, we will use a VSV-pseudotyped replication defective HIV-1 gag/pol deletion construct to transduce HPT-1 cells. Following transduction, we will use representational difference analysis (RDA) and oligonucleotide expression micrarrays to determine the cellular genes that are differentially expressed following transduction by HIV-1. Differential expression of cellular genes will be confirmed by standard molecular techniques. Once host candidate genes are identified, we will transduce HPT-1 cells with a series of HIV-1 multigenic mutant constructs to map the specific HIV-1 genes responsible for the observed alterations in cellular gene expression. These studies should elucidate essential mechanisms of HIV-1 pathogenesis in HIVAN. It is also possible that genes implicated in the pathogenesis of HIVAN maybe important factors contributing to the marked predisposition of African-Americans to nearly all causes of renal failure.